Pyroxylin enamel



Patented Feb. 23, 1932 UNITED PATENT QIF FRANK c. norrmaiv, OFSOUTHannoy, NEWJEBSEY, AssIeN-oa'ro nu :eour n11 Nobrawiiig.

ivnmouns &. comrANY, or warmrneron, DELAWARE, A coaronn rron or'p nnawanna" Thisinvention relates-ta coating compositions and moreparticularly it relates to a special composition tobe added to pyroxylinenamels to mo dify their usual characteristics,

ral aging and cracking, enamels known as crackle enamels have beendeveloped. These are lacquer enamels in which the pigment content is sogreat that it cannot be kept together by the lacquer binder with theresult that .when they are applied by spraying or otherk wise to alacquer ground coat, they split apart in irregular cracks, showing thecolor of the ground coat underneath. The finish thus produced has anaged, cracked or checked ap- Ipearance. Hereto-fore, crackle enamelshave been produced by compounding the desired ingredients according to avariety of formulas. The enamels thus produced accordingly made up aspecial class of products and it has been necessary for those handlingthese materials in stock to carry a double line of enamels, oneconsisting of ordinary enamels and the other consisting of a line ofspecially compounded crackle enamels.

This invention has as an object to provide a special product oringredient which may be added to any of the usual types of pyroxylinenamels to modify their usual characteristics on drying. A furtherobject is to make pos- Isible the conversion of the ordinary pyroxylinenamels into crackle enamels by the simple operation of mixing a singleingredient therewith. Other objects will appear hereinafter.

.These objects are accomplished by the fol- :lowing invention whichincludes mixing a finely divided soap with a nitrocellulose solvent orthinner.

Throughout this specification for the purpose of more particularlydescribing the char- .acter of my special product, I shall refer to itas a crackle base. i

In carrying out this invention, a metallic soap, such for example, as analuminum soap, is mixed with a solvent such as ethyl acetate.

:The mixture is then ground in a porcelainr moxxmn ENAMELApplidationfiled August-28,1928. Serial No. 302,64

lined mill, using flint pebbles a the grinderi It is-to be understood,of course, that the method of grinding which may beemployed provided thesoap is properly groundand is not greatly discolored. In the grindingopn, a small quan i y o pyroxy inmay be added, i fdesired, in order togive body to the grin n x ur h ryr x-y inmay.

be omitted altogether,=hovv.ever, since it is] merely. a aes e -y t the112Qund g-0iithe special ingredient of this invention;

Th prqp rt ns o mate ia s u ed h i J35 aried i in W de m ts, bu hefqllowia xampl i e ven a i lu trating theirroperens used in one o thepreerred mbqd v ments o my inWn lQIl- In th -e ample given abate, the so vet a be s b t u edby "o h s ient than ethyl 'cemtei' apable o d s l ngayesl1n,b ut it-shoul'd be carefully selected forc ase t sell. ur ngee's 3 3 .of th Example Per cent I, Aluminum stearate i "f Ethyl-acetate,74.5 Pyroxylin .5

d'er that the qualities of th gqrackle base will nh fi al qh n este fmaye ne les.

asclventinfih .ferm a iq .withsatistactcry' lt l ob unde s oodq h v i iwit in as op o myin ent on t u e-eithenseaps then results. 2

aluminum stear atef compounding j y rack base E9 inst n so psiorfi edlbyr, H I95. uminum wi eth r fat aid han stati a b subst uted fa al a e Parc the lumi um tearat given in .l .eaamnla if:

h imer tie of efihe m t haa a e i si ed lausaathe cra kl ha ae lmy-iinaen iea the proportions by weight of this material to thepyroxylin enamel to which it is added varies from 60% to 40%. However,these proportions are flexible and may be varied to suit the particulartype ofenamel with which it is desired to mix the base. When thinningthe mixture of enamel and crackle base, it is desirable to use ethylacetate or some other readilyvolatile solvent in order tohasten thedrying speed.

It will thus be seen that I have provided a special product which makesit possible easily and quickly to convert the ordinary types ofpyroxylin enamels to the type known as crackle enamels. This eliminatesthe 1necessity, which has heretofore existed, of deal-" ersin theseenamels carrying a double line of materials; All that is now necessaryis to stock the usual line of enamels and a quantity of the specialcrackle base of my invention'.v When it is desired to produce 'a cracklefinish with any of the usual types of enamels, they may be combined[with the crackle base in the proportions indicated by of producing acoating" aliphatic alcohols and esters, the second composition beingadded in such amount that the aluminum stearate in the final compositionis between 10% and 15% by weight of the first composition. V I

4.'Ihe method of producing acoatin'g composition that will produce acrackle-finish comprising adding to a completed cellulose nitratecoating composition a second compo? sition comprising finely dividedaluminum stearate suspendedin ethyraeeme, the second composition beingadded in such amount that the aluminum stearate in the final compositionis between 10% to 15% by weight of;

the first composition. V e "5. The method of producing a coatingcomnitrate coating composition from 40% to 60% by weight thereof of acomposition compfising approximately by weight 25% aluminum positionthat will produce a-crackle 'finishf comprising adding to a completedcellulose] stearate, 74.5%"ethyl acetate and 0.5% eel lulose nitrate.

In testimony whereof, afiix my signature.

I FRANK c. HOFFMAN.

composition that will produce a crackle finish comprising adding to acompleted cellulose nitrate coating composition a second compositioncomprising finely divided soap suspendedin' a cellulose nitra'te solventfrom the.

group consisting-of aliphatic alcohols and esters,-the secondcomposition being added in such amount thatthe soap in the finalcomposition is between 10% to 15% by weight of the first composition.

2. ,The method of producing a coating com-, position that will produce acrackle finish comprising adding to a completed cellulose nitratecomposition a second composition comprising fin'ely divided aluminumstearate suspended. in a cellulose nitrate solventffroni a groupconsisting of aliphatic alcohols and esters, the second compositionbeing added in such amount that the aluminum stearate in the finalcomposition is between 10 to 15% by weight of the first composition. c

3.- The method of producing a coating com-' position that will produce acrackle finish comprising adding toa completed cellulose nitrate coatingcomposition a second composition comprising finely divided aluminumstearate, cellulose nitrate, and a cellulose ni- I trate solvent fromthe group consisting of

